This proposal deals with the design and preparation of radiopharmoceuticals potentially useful for imaging tumors of steroid target organs such as the adrenal, mammary and prostate glands. Thin-layer chromatography, high pressure liquid chromatography and nuclear magnetic resonance spectroscopy will be used to purify, identify and quantitate the proposed agents. The kinetics of distribution of the F-18 labeled agents will be studied in experimental animals in order to obtain the information necessary to allow their evaluation as potential radiopharmaceuticals for imaging steroid target organs.